Vehicle systems may use a variety of methods to determine locations of the vehicles as the vehicles move along routes. For example, rail vehicles may use global positioning system receivers and/or radio frequency identification (RFID) tags installed along a railway track to determine the locations of the vehicles. The vehicles may interrogate the RFID tags with an RFID reader to determine the location of the vehicle along the route. For example, the tags may be programmed with a location value. The location value may represent a distance or location of the tag along the route. For example, a location value of 500 that is programmed into a tag may indicate that tag is 500 meters from a designated location along the route.
Some tags may be installed in incorrect locations or become misplaced during maintenance of the route. Some tags may be programmed with the correct location information, but due to error in replacing the tags when the tags are moved to perform maintenance on the route, the tags may be inadvertently placed in incorrect locations along the route. For example, the locations of two tags may be inadvertently switched. These tags may be referred to as misplaced tags.
Some vehicles rely in the reading of these tags to ensure safe operation of the vehicles. For example, rail vehicles may read the tags to determine where the vehicles are located and/or what direction the vehicles are traveling along the route. The vehicle location and/or direction of travel that is determined from the tags may then be used to determine how fast the vehicles are allowed to travel, whether the vehicles are allowed or prohibited from entering into certain locations, whether brakes of the vehicles should be automatically engaged in that location, or the like. Misplaced tags can provide incorrect location information to the vehicles and, as a result, pose a significant safety risk.